Tap.



ma m

R. S. BASCOM.

TAP,

APPUCATION FILED JAN-25,1917.

Patented July 10, 1917.

3 hum M701 FaZZ/n J. fiascam ill E ST S A Fi ROLLIN S. BASCOM, OF GREENFIELD, MASSACHUSETTS, ASSIGNOB, TO GREENFIELD TAP AND DIE CORPORATION, OF GREENFIELD, MASSACHUSETTS.

TAP.

Application filed January 25, 1917.

; have invented new and useful Improvements in Taps, of which the following is a. specification.

M invention relates to revoluble cutting tools, such as taps.

An object of my invention is to provide a reversible tool having independent sets of cutting edges, one or other of which sets comes into operation according to the direction in which the tool is revolved. Another ob'ect is to orovide a split annular cuttin a. D

' is no tendency while the cutting operation is being performed, to cause expansion of the annular member beyond the size to which it is adjusted.

With these principal objects in view, my invention consists in the construction, combination and arrangement of parts herein illustrated, described and claimed.

in the accompanying drawings forming part hereof, in which the same reference characters designate corresponding parts in all views, I have shown my invention as applied to a tap.

Figure 1 is an elevation of a tap embodying the invention.

Fig. 2 is plan of the cutting member viewed from the bottom as shown in Fig. 1;

Fig. 3 is a section on line 8-3 of Fig. 2; and,

Fig. i is an elevation of the shank showing partly in section the means for retaining the cutting member on the shank.

Referring to the drawing, the annular cutting member 1 is provided in the usual manner with projections 52 upon which the cutting edges are formed, and these projections are provided on one edge with teeth 3, which cut when the tool is revolved in one direction, and on the other edge with teeth 1 which cut when the tool is revolved in the other direction.

The cutting member is split at 5, and at this same point is a tapered bore 6 approximately parallel to the axis of the member 1 into which fits a tapered pin 7 by means of which the parts of the cutting member ad- Specification of Letters Patent.

Patented July 10, 1917.

Serial No. 144,361.

jacent the split can be separated to increase the diameter of the cutting member, thus compensatlng for wear.

The annular cutting member is supported upon a. shank 8, the central hole thereof fitting over the portion 9 of the shank and bearing snugly against the shoulder 10. The member 1 is retained upon the shank 8 by means of a screw 11 which screws axially into the end of the shank 8 and which is provided with a head larger than the central hole of the annular member, so that the member 1 is held in place against the shoulder 10. The member 1 is preferably provided with a recess or counter sunk portion 12 into which the head of the screw 11 fits.

The shank 8 is provided with a pin or proj ection 13 adapted to fit into one or the other of the holes 1 1, 15 of the member 1 when the member is in place upon the shank. These holes 14; on one face and 15 on the other are disposed on the member 1 near the split 5, and rearwardly thereof with respect to the direction of rotation, so that when the tap is revolved the pin 13 follows the split 5.

The reason for this particular disposition of the holes 14, 15 is to overcome the tendency for the annular member to be forced to assume a larger diameter should any of the cutting edges catch or bind upon the work, which would happen if the pin were disposed in any other location. By this construction, the binding of any cutting edge cannot alter the diameter of the cutting member, as its only tendency would be to force the following part of the cutting member inward and reduce the diameter, which cannot happen on account of the adjusting pin 7 which maintains the diameter at a cletermined point.

The hole 14 is provided on one face of the tap, and the hole 15 upon the other so that the tap may be reversed in position upon the shank to allow of either set of cutting teeth being used. The shank 8 is preferably provided with a square head or other means 16 by which it can be rotated.

Having now described my invention what I claim and desire to secure by Letters Patent is:

1. In a revoluble cutting tool, the combination comprising a shank, a split annular cutting member disposed on said shank, and means of connection between said member and said shank disposed adjacent to said split, and rearwardly thereof with respect to the direction of rotation.

2. In a revoluble cutting tool, the combination comprising a shank, a split annular cutting member disposed on said shank, means for adj ustably separating the parts of said member at said split, and means of connection between said member and said shank disposed adjacent to said split, and rearwardly thereof with respect to the direction of rotation.

3. In a revoluble cutting tool, the combination comprising a shank, a split annular Cutting member removably and reversibly disposed on said shank, and means of connection between said member and said shank disposed adjacent to said split, and rearwardly thereof with respect to the direction of rotation.

4:. In a revoluble cutting tool, the combination comprising a shank, an annular cutting member remo'vably and reversibly disposed on said shank, means for varying the diameter of said member, and means of connection between said member and said shank disposed adjacent to said split, and rearwardly thereof with respect to the direction of rotation.

5. In a revoluble cutting tool, the combination comprising a shank having a projec tion, and a radially split annular cutting member disposed on said shank and provided with a hole adapted to engage said projection, said hole being disposed adjacent to and rearwardly of said split with respect to the direction of rotation.

6. In a revoluble cutting tool, the combination comprising a shank having a shoulder, a pin depending from said shoulder, and a split annular cutting member removably and reversibly disposed on said shank abutting said shoulder, said member having holes for alternative engagement with said pin disposed in its upper and lower faces adjacent to and rearwardly of said split with respect to the direction of rotation.

In testimony whereof I have signed my name to this specification.

ROLLIN S. BASCOM.

Witness SAMUEL D. 'CoNAN'r.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, I). C. 

